Air Compressor

ABSTRACT

An air compressor includes a cylinder housing with a piston slidably disposed in a compression chamber of the cylinder housing for generating pressurized air. The air compressor further includes an air drum receiving the cylinder housing and engaged with a flange extending outwardly from a peripheral wall of the cylinder housing. An expanded chamber for storage of the pressurized air is formed between the air drum and the cylinder housing and being in communication with the compression chamber of the cylinder housing. The expanded chamber has significantly larger volume which reduces resistance applied to the piston during reciprocation in the cylinder housing and increases air compression efficiency.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an air compressor and, more particularly, to an air compressor which is characteristic of lesser resistance applied to a piston reciprocating in a cylinder housing of the air compressor and better air compression efficiency.

2. Description of the Related Art

The inventor has been making all efforts in researching air compressors, such as U.S. Pat. No. 5,655,887 to Chou, U.S. Pat. No. 6,146,112 to Chou, U.S. Pat. No. 6,200,110 to Chou, U.S. Pat. No. 6,551,077 to Chou, U.S. Pat. No. 6,655,928 to Chou, U.S. Pat. No. 6,846,162 to Chou, U.S. Pat. No. 7,462,018 to Chou, U.S. Pat. No. 6,095,758 to Chou, U.S. Pat. No. 6,135,725 to Chou, U.S. Pat. No. 6,213,725 to Chou, U.S. Pat. No. 6,280,163 to Chou, U.S. Pat. No. 6,315,534 to Chou, U.S. Pat. No. 6,059,542 to Chou, U.S. Pat. No. 6,295,693 to Chou, U.S. Pat. No. 6,413,056 to Chou, U.S. Pat. No. 6,514,058 to Chou, and U.S. Pat. No. 7,240,642 to Chou, and in reconstructing typical air compressors to have simplified and easily assembled structures and better efficiency.

A conventional air compressor relies on reciprocation of a motor-driven piston inside a cylinder housing to convey pressurized air to an air drum at an upper end of the cylinder housing. Manifolds are provided on the air drum and connected with hoses for the purpose of air delivered to objects ready to be inflated. However, the conventional air drum has an inner diameter less than that of a compression chamber in the cylinder housing so that a valve seat within between the cylinder housing and the air drum must bear stronger pressure in the direction opposite to an applied force, which adversely influences speed of the piston reciprocating in the compression chamber and reduces air compression efficiency.

BRIEF SUMMARY OF THE INVENTION

Thus, an objective of the present invention is to provide an air compressor with both a cylinder housing and an air drum newly designed in which a valve seat suffers from lesser resistance against an applied force, while having fewer negative effects of reacting forces on a piston reciprocating in the cylinder housing and obtaining better air compression efficiency.

To achieve this and other objectives, an air compressor of the present invention includes a cylinder housing and an air drum. The cylinder housing is installed on a support and includes a peripheral wall, a top wall, and an opening spaced from the top wall along a longitudinal axis. The cylinder housing further includes a compression chamber therein. A piston is slidably disposed in the compression chamber for generating pressurized air. The top wall includes a vent through which the pressurized air in the cylinder housing can be guided outwardly. The air drum receives the cylinder housing and is engaged with the peripheral wall of the cylinder housing. The air drum includes upper and lower ends spaced along the axis, and the upper end is higher than the top wall of the cylinder housing along the axis. The air drum further includes a first segment below the top wall along the axis and a second segment above the top wall along the axis. A first air storage chamber is formed between the first segment and the peripheral wall of the cylinder housing, and a second air storage chamber is formed in the second segment and in communication with the compression chamber of the cylinder housing through the vent. An inner diameter of the second air storage chamber is greater than an outer diameter of the cylinder housing.

In a preferred form, a length of the air drum along the axis is greater than a length of the cylinder housing along the axis. A flange extends outwardly from the peripheral wall of the cylinder housing, and the lower end of the air drum is coupled with the flange of the cylinder housing.

The present invention will become clearer in light of the following detailed description of illustrative embodiments of this invention described in connection with the drawings.

DESCRIPTION OF THE DRAWINGS

The illustrative embodiments may best be described by reference to the accompanying drawings where:

FIG. 1 is a perspective view of an air compressor according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the air compressor of FIG. 1.

FIG. 3 shows a schematic cross-sectional view of the air compressor of FIG. 1, with a top cap separated from an air drum in FIG. 2.

FIG. 4 is a schematic illustration showing inner diameters of both a cylinder housing and the air drum in FIG. 3.

FIG. 5 is a schematic cross-sectional view illustrating a backward motion of a piston in FIG. 2.

FIG. 6 is a schematic cross-sectional view illustrating a forward motion of the piston in FIG. 5.

FIG. 7 is a schematic cross-sectional view of an air compressor according to a second embodiment of the present invention.

FIG. 8 is a schematic cross-sectional view of an air compressor according to a third embodiment of the present invention.

FIG. 9 is a schematic cross-sectional view of an air compressor according to a fourth embodiment of the present invention.

FIG. 10 is a schematic cross-sectional view of an air compressor according to a fifth embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

An air compressor according to a first embodiment of the present invention is shown in FIGS. 1 through 6 of the drawings and includes a support 10, an actuating unit installed on the support 10, a cylinder housing 2 integrally engaged with the support 10, and a piston 16 slidably held within the cylinder housing 2. The actuating unit includes a motor 11, a pinion 12 mounted on a spindle of the motor 11, a gearwheel 13 meshing with the pinion 12, a flywheel 18 with a crankpin 14, and a cooling fan 17. The crankpin 14 is coupled with a piston rod 15 of the piston 16 so that the piston 16 can be driven by the motor 11 and performs a reciprocating motion inside and relative to the cylinder housing 2.

The cylinder housing 2 includes a peripheral wall 20, a top wall 21, and an opening 24 spaced from the top wall 21 along a longitudinal axis (X), defining a compression chamber 26 in the cylinder housing 2 (FIG. 3). The top wall 21 extends in a first horizontal direction (L1) perpendicular to the axis (X) and is provided with a vent 22. An annular boss 23 protrudes outwardly from an outer surface of the top wall 21, and a cavity 230 is formed in the boss 23 and in communication with the compression chamber 26 through the vent 22. A valve seat 31 is movably accommodated in the cavity 230 and has an outer diameter less than an inner diameter of the cavity 230 but greater than an inner diameter of the vent 22. A gap 231 is formed between the valve seat 31 and the boss 23 (FIG. 2). A flange 27 extends outwardly from a lower end of the peripheral wall 20 which defines the opening 24 and extends in a second horizontal direction (L0) perpendicular to the axis (X) and parallel to the first horizontal direction (L1).

The air compressor of the present invention further includes an air drum 6 receiving the cylinder housing 2 and sharing the identical central axis (X) with the cylinder housing 2. The air drum 6 includes upper and lower ends 61 and 611 spaced along the axis (X). In this embodiment, the air drum 6 is extended upward from an outer periphery of the flange 27 along the axis (X) with the lower end 611 integrally engaged with the flange 27 of the cylinder housing 2. The upper end 61 of the air drum 6 is higher than the top wall 21 of the cylinder housing 2, so that a length (H2) of the air drum 6 along the axis (X) is greater than a length (H1) of the cylinder housing 2 along the axis (X), and an expanded chamber 605 for storage of pressurized air is formed between the air drum 6 and the cylinder housing 2 and is in communication with the compression chamber 26 of the cylinder housing 2 through the vent 22. In this embodiment, the upper end 61 of the air drum 6 includes an opening 60 formed therein, and a circular top cap 51 is engaged to the upper end 61 for sealing the chamber 605. Furthermore, an engagement flange 62 is extended outwardly from a periphery of the upper end 61 of the air drum 6 and provided with a plurality of positioning holes 63 spaced in a peripheral direction thereof and an annular groove 64 in an outer end surface thereof. The top cap 51 is provided with a plurality of positioning holes 52 and an annular groove 54 in an inner end surface of the top cap 51. An annular rubber gasket 95 is mounted in the grooves 54, 64, and a plurality of bolts 94 is extended through positioning holes 52 in the top cap 51 and positioning holes 63 in the engagement flange 62 to securely couple the top cap 51 with the upper end 61 of the air drum 6. Further, the top cap 51 includes a protrusion post 53 formed on the inner end surface thereof and extending toward the cylinder housing 2 along the axis (X). A spring 32 is mounted around the protrusion post 53 and between the top cap 51 and the valve seat 31 for biasing the valve seat 31 toward the top wall 21 of the cylinder housing 2. In this embodiment, the air drum 6 includes a first segment 601 below the horizontal line L1 of the top wall 21 and a second segment 602 above the top wall 21 (see FIG. 3). An annular first air storage chamber 6011 is formed between the first segment 601 and the peripheral wall 20 of the cylinder housing 2, and a second air storage chamber 6012 is formed inside the second segment 602, so that the first and second air storage chambers 6011 and 6012 are included in the chamber 605 of the air drum 6, and the inner diameter D3 of the second air storage chamber 602 is greater than both the inner diameter D1 and the outer diameter D2 of the cylinder housing 2.

Additionally, a plurality of manifolds 67, 68, 69 is provided on and extended outwardly from the air drum 6 and in communication with the chamber 605 of the air drum 6. The manifolds 67, 68, 69 may be connected with hoses or installed with various kinds of facilities that require pressurized air supplied thereto such as pressure gauges, air nozzles, safety valves, relieves, etc. In this embodiment, the manifold 67 is used to link a hose 91 on which there is an air nozzle (not shown) installed to connect an object ready to be inflated, and the manifolds 68, 69 are used for installation of a release valve 92 and a pressure gauge 93 respectively.

In practice, the piston 16 is driven by the motor 11 to perform reciprocation inside the compression chamber 26 of the cylinder housing 22. Outside air will be introduced into the compression chamber 26 of the cylinder housing 22 during a backward motion of the piston 16 (see FIG. 5). The pressurized air in the compression chamber 26 which passes through the vent 22 of the cylinder housing 2, moving the valve seat 31 and compressing the spring 32 during a forward motion of the piston 16 is fed into the chamber 605 of the air drum 6 via the gap 231 between the valve seat 31 and the boss 23 and into objects with various features and functions (as shown in FIG. 6) via the manifolds 67, 68, 69. The valve seat 31 which compresses the spring 32 is retained by the protrusion post 53 of the top cap 51 and positioned at a specific position.

Since the inner diameter D3 of the second air storage chamber 6012 of the chamber 605 in the air drum 6 is greater than the inner diameter D1 of the compression chamber 26 in the cylinder housing 2 and the chamber 605 further includes the first air storage chamber 6011, the chamber 605 in the air drum 6 has a total volume greater than that of the compression chamber 26 in the cylinder housing 2, which effectively reduces resistance applied to the piston 16 during reciprocation, accelerates speed of the piston 16, and substantially increases efficiency of air compression.

Now that the basic teachings of the present invention have been explained, many extensions and variations will be obvious to one having ordinary skill in the art. The air compressor shown in FIG. 7 is a modification of that shown in FIGS. 1 through 6. Description of the parts of the air compressor shown in FIG. 7 identical to those shown in FIGS. 1 through 6 is omitted. In particular, the boss 23 in the second embodiment has a length along the axis (X) elongated until the inner end surface of the top cap 51, and the boss 23 is provided with a through-hole 6032 for stream of pressurized air. The boss 23 includes a cavity 6030 therein to accommodate the valve seat 31 and the spring 32 with two ends of the spring 32 abutting against the top cap 51 and the valve seat 31 respectively. The longer boss 23 allows both the spring 32 and the valve seat 31 to be stably held for sealing the vent 22. Additionally, a gap 6031 is formed between the valve seat 31 and the boss 23, so that the pressurized air can pass through the vent 22 and the gap 6031 and is guided into the chamber 605 of the air drum 6 as well as objects which are connected to the manifolds 67, 68, 69 via the through-hole 6032.

FIG. 8 illustrates an air compressor according to a third embodiment of the present invention wherein the flange 27 extending from the peripheral wall 20 of the cylinder housing 2 is located between the top wall 21 and the opening 24 along the axis (X) and extends in the second horizontal direction perpendicular to the axis and parallel to the first horizontal direction. The chamber 605 of the air drum 6 still includes the annular first air storage chamber 6011 and the second air storage chamber 6012 with its inner diameter D3 larger than that of the compression chamber 26 in the cylinder housing 2.

The cylinder housing 2 and the air drum 6 shown in FIG. 9 illustrates another modification of that shown in FIGS. 1 through 6 wherein the air drum 6 is detachably engaged with the cylinder housing 2. The flange 27 extends from the lower end of the peripheral wall 20 of the cylinder housing 2 and is provided with a plurality of positioning holes 28 and an annular groove 281 in an inner end surface of the flange 27. The air drum 6 includes a sealed upper wall 610 on the upper end 61 thereof and an opening 603 in the lower end 611 thereof. The air drum 6 is provided with a protrusion post 66 extending downward from the upper wall 610, and the lower end 611 of the air drum 6 extends outwardly for development of the engagement flange 62 in which there are a plurality of positioning holes 63 and an annular groove 64 in its inner end surface. The air drum 6 can be securely coupled with the cylinder housing 2 by an annular rubber gasket 95 embedded in the grooves 281, 64 as well as a plurality of bolts 94 extending through the positioning holes 28, 63. The chamber 605 of the air drum 6 still includes the first air storage chamber 6011 and the second air storage chamber 6012 as shown in FIG. 2.

FIG. 10 illustrates an air compressor according to a fifth embodiment of the present invention wherein the manifolds 67, 68, 69 in FIG. 2 are not installed on the air drum 6 but on an air drum seat 82 including an air channel 87 therein. The air drum seat 82 is extended outwardly from the top cap 81, and the air channel 87 communicates the chamber 605 of the air drum 6 with the plurality of manifolds 85, 86. During reciprocation of the piston 16, pressurized air is guided into the chamber 605 of the air drum 6 and fed into the object ready to be inflated through the air channel 87, the manifold 86, and the hose 91.

In virtue of design of the air drum 6 of the present invention, the piston 16 suffers from obviously reduced pressure only and is accelerated during reciprocation, so that the air compressor of the present invention has better air inflation efficiency, spends lesser time in inflating objects, and has extended service life.

Thus since the invention disclosed herein may be embodied in other specific forms without departing from the spirit or general characteristics thereof, some of which forms have been indicated, the embodiments described herein are to be considered in all respects illustrative and not restrictive. The scope of the invention is to be indicated by the appended claims, rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein. 

1. An air compressor, comprising: a cylinder housing installed on a support and including a peripheral wall, a top wall, and an opening spaced from the top wall along a longitudinal axis, with the cylinder housing further including a compression chamber therein, with a piston slidably disposed in the compression chamber for generating pressurized air, with the top wall including a vent through which the pressurized air in the cylinder housing can be guided outwardly, and an air drum receiving the cylinder housing and engaged with the peripheral wall of the cylinder housing, with the air drum including upper and lower ends spaced along the axis. with the upper end higher than the top wall of the cylinder housing along the axis, with the air drum further including a first segment below the top wall along the axis and a second segment above the top wall along the axis, with a first air storage chamber formed between the first segment and the peripheral wall of the cylinder housing, with a second air storage chamber formed in the second segment and in communication with the compression chamber of the cylinder housing through the vent, with an inner diameter of the second air storage chamber being greater than an outer diameter of the cylinder housing.
 2. The air compressor according to claim 1, with a length of the air drum along the axis being greater than a length of the cylinder housing along the axis, with a flange extending outwardly from the peripheral wall of the cylinder housing, and with the lower end of the air drum integrally coupled with the flange of the cylinder housing.
 3. The air compressor according to claim 2, with the top wall extending in a first horizontal direction perpendicular to the axis, and with the flange extending outwardly from a lower end of the peripheral wall and extending in a second horizontal direction perpendicular to the axis and parallel to the first horizontal direction.
 4. The air compressor according to claim 2, with the top wall extending in a first horizontal direction perpendicular to the axis, and with the flange located between the top wall and the opening of the cylinder housing along the axis and extending in a second horizontal direction perpendicular to the axis and parallel to the first horizontal direction.
 5. The air compressor according to claim 2, with an annular boss protruding outwardly from an outer surface of the top wall, with a cavity formed in the boss and in communication with the vent, with a valve seat movably accommodated in the cavity and having an outer diameter less than an inner diameter of the cavity but greater than an inner diameter of the vent, and with a gap formed between the valve seat and the boss.
 6. The air compressor according to claim 5, with the upper end of the air drum including an opening formed therein, with a top cap engaged to the upper end of the air drum, with the top cap including a protrusion post formed on an inner end surface thereof and extending toward the cylinder housing along the axis, and with a spring mounted around the protrusion post and between the top cap and the valve seat for biasing the valve seat toward the top wall of the cylinder housing.
 7. The air compressor according to claim 6, with an engagement flange extended outwardly from a periphery of the upper end of the air drum and provided with a plurality of positioning holes spaced in a peripheral direction thereof, with an annular groove formed in an outer end surface of the engagement flange, with the top cap provided with a plurality of positioning holes and an annular groove in an inner end surface of the top cap, with an annular rubber gasket mounted in the annular grooves of the engagement flange and the top cap, and with a plurality of bolts extending through the positioning holes in the top cap and the engagement flange to securely couple the top cap with the upper end of the air drum.
 8. The air compressor according to claim 6, with the boss having a length along the axis elongated until the inner end surface of the top cap, and with the boss provided with a through-hole for stream of the pressurized air.
 9. The air compressor according to claim 6, with a plurality of manifolds extended outwardly from the air drum and being in communication with the second air storage chamber of the air drum.
 10. The air compressor according to claim 6, with an air drum seat extended outwardly from the top cap and including an air channel therein, with a plurality of manifolds installed on the air drum seat, and with the air channel communicating the second air storage chamber of the air drum with the plurality of manifolds.
 11. The air compressor according to claim 1, with a length of the air drum along the axis being greater than a length of the cylinder housing along the axis, with the air drum further including an upper wall formed on the upper end thereof and an opening in the lower end thereof, with a flange extending outwardly from the peripheral wall of the cylinder housing, and with the lower end of the air drum detachably engaged with the flange of the cylinder housing.
 12. The air compressor according to claim 11, with the top wall extending in a first horizontal direction perpendicular to the axis, and with the flange extending outwardly from a lower end of the peripheral wall and extending in a second horizontal direction perpendicular to the axis and parallel to the first horizontal direction.
 13. The air compressor according to claim 12, with a plurality of manifolds extended outwardly from the air drum and being in communication with the second air storage chamber of the air drum.
 14. The air compressor according to claim 13, with the flange of the cylinder housing provided with a plurality of positioning holes and an annular groove in an inner end surface of the flange, with an engagement flange extending outwardly from the lower end of the air drum and provided with a plurality of positioning holes and an annular groove in an inner end surface of the engagement flange, with an annular rubber gasket mounted in the annular grooves of the flange and the engagement flange, and with a plurality of bolts extending through the positioning holes in the flange and the engagement flange to securely engage the air drum with the cylinder housing.
 15. The air compressor according to claim 14, with an annular boss protruding outwardly from an outer surface of the top wall, with a cavity formed in the boss and in communication with the vent, with a valve seat movably accommodated in the cavity and having an outer diameter less than an inner diameter of the cavity but greater than an inner diameter of the vent, with a gap formed between the valve seat and the boss, with the air drum further including a protrusion post extending downward from the upper wall thereof, and with a spring mounted around the protrusion post for biasing the valve seat toward the top wall of the cylinder housing. 